1. Field
Example embodiments relate to an optoelectronic device, and an image sensor and an electronic device including the same.
2. Description of the Related Art
An optoelectronic device is a device requiring a charge exchange between an electrode and a photoelectric conversion layer by using holes or electrons.
An optoelectronic device may be classified as follows. A first optoelectronic device is an electronic device driven by generating excitons in a photoelectric conversion layer by photons from an external light source, separating the excitons into electrons and holes; and transferring the electrons and holes to different electrodes as a current source (voltage source). A second optoelectronic device is an electronic device driven by applying a voltage or a current to at least two electrodes to inject holes and/or electrons into a photoelectric conversion layer at an interface of the electrodes, and driving the device by the injected electrons and holes.
The optoelectronic device has a structure in which a photoelectric conversion layer including a functional inorganic or organic material is interposed between an anode and a cathode. The optoelectronic device may include a buffer layer (e.g., a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL)) between an anode and a photoelectric conversion layer or a cathode and a photoelectric conversion layer, in order to improve efficiency and stability.
An organic optoelectronic device including a photoelectric conversion layer containing an organic material has relatively low external quantum efficiency in a visible light region and a relatively high dark current due to internal impurities in the organic material compared with an inorganic optoelectronic device including an inorganic oxide. The relatively high dark current may increase the leakage current of the organic optoelectronic device, and thus deteriorate the sensitivity of the organic optoelectronic device as well as accuracy of the external quantum efficiency converted from a photocurrent during the photoreaction.
Accordingly, development of an organic optoelectronic device capable of decreasing the dark current is needed.